Effect of temperature on thickness of starch- and gum-based thickened liquids for dysphagic individuals

Objectives: Studies have revealed that consistency of liquid food changes with temperature. Yet, the exact relationship between temperature and consistency of food bolus is still not known. The present study examined the change in liquid consistency with temperature. Methods: Water thickened at the four thickness levels (slightly thick, mildly thick, moderately thick, and extremely thick) using starch-based and xanthan-gum-based thickeners was studied. Consistency was measured using a Bostwick consistometer at different temperature points between 5 degrees C and 85 degrees C. Regression analyses were subsequently carried out. Results: Results indicated definite but different relationships between temperature and consistency of thickened liquids prepared using starch- and gum-based thickeners. While there was a general trend of decreasing consistency in liquids prepared using gum-based thickener with temperature, a quadratic relationship between temperature and consistency was found for starch-based thickener. The consistency was generally the highest at very low and very high temperature, but the lowest at 65 degrees C. Conclusion: Findings confirmed a definite effect of temperature on bolus consistency. When preparing thickened liquids for patients with dysphagia, caregivers and clinicians should take into consideration the effect of temperature, as it has a definite effect on liquid consistency.